0.1.2 • Published 14h ago

@murmurv2/security

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Murmur

Named after murmuration — the mesmerizing phenomenon where thousands of birds communicate and move as one.
Murmur brings the same coordinated communication to AI agents.

Encrypted agent-to-agent messaging. Let your AI models talk to each other.

A secure multi-agent communication bus for Claude Code, Codex, and any MCP-capable agent — across machines, across organizations, end-to-end encrypted over NATS.

Install · Quick Start · How It Works · Features · MCP Tools · Deployment · Contributing

Murmuration — from nature's coordinated flight to AI agent communication

Why "Murmur"?

A murmuration is one of nature's most extraordinary phenomena — thousands of starlings flying as a single, fluid organism without any central coordinator. Each bird follows simple local rules: match your neighbors' speed, stay close, don't collide. From these simple interactions emerges breathtaking coordinated behavior.

Murmur applies the same principle to AI agents. No central orchestrator. No human relay. Each agent communicates directly with its peers through encrypted channels — and from these simple peer-to-peer interactions, complex collaborative workflows emerge. Code reviews, research tasks, architectural decisions — all happening autonomously between Claude, GPT, Gemini, or any other model, while you sleep.

What's New in v2.11

Set up a connection in the app. On Mac and Windows, accept an invitation, save the reply, start the service and choose your AI client through the app. Existing profiles and interrupted setup can be recovered without recreating their identity.
A Windows installer and a prebuilt CLI. The per-user setup.exe installs the app and its shortcuts. The @murmurv2/cli package supplies the murmur command without compiling on your machine; see its publication status below.
Clearer connection and wake status. The app separates service readiness, message delivery and a returned reply. Claude Code's configured Stop hook listens while the client is idle; Claude Desktop and Codex on Windows still need an active client turn. See known limitations.

What's New in v2.10

Three stable release assets. Choose murmur-runtime-2.10.0.zip for the portable CLI, daemon and MCP runtime, Murmur-Windows-2.10.0-x64.zip for the Windows x64 companion, or Murmur-Mac-2.10.0-universal.dmg for macOS on Intel or Apple Silicon. Node.js 22.13.0 or newer remains an external prerequisite for every asset.
Updates remain manual. Murmur can open the stable release page after an explicit click. It does not download, install, replace or restart the runtime, native app, service or profile.

What's New in v2.9

Exactly-once wake delivery. A failed wake used to be marked handled — the cursor advanced from finally, lived only in memory and re-seeded at the table tip on restart — and a retried relay could answer twice. Now every inbound delivery is one durable row (delivery_id UNIQUE, committed with its wake state in one transaction), a redelivered envelope is ACKed without a second wake, the ACK follows the durable commit instead of the end of the Codex turn, failed wakes retry under the same id with backoff and then dead-letter visibly, the cursor is the highest contiguous settled row, and the relay reply id is derived from the inbound msgId so a retry never starts the turn twice. Design by @alexanderyswork in #96. (v2.9.0)
Codex turn outcome is read, not assumed. turn.status / turn.error from turn/completed are surfaced; a failed turn is retried, an interrupted one is not, and an empty final answer is a failed wake, not a wake final relayed log line. (v2.9.0)
Lanes instead of one line. A long turn for one peer no longer holds every other inbound message: wakes run in lanes per (peer, conversation), up to wake.concurrency at once (default 4), ordered within a lane. (v2.9.0)
Codex threads per conversation, remembered across restarts. Seeded threads are keyed by (peer, conversation) and persisted in wake_threads; a static peer.threadId stays an explicit pin. (v2.9.0)
The cold-start watcher stands down while a session is alive. codex-murmur-coldstart-watch.py checks the app-server socket and session_presence before spawning a headless Codex. (v2.9.0)
Phase N member routing and Codex Desktop exact-task delivery — signed channelId / senderMemberId / addresseeMemberId through the whole path, and opt-in delivery to the exact Desktop task via codex queue. By @fedoseevstanislav. (v2.9.0)

What's New in v2.8

Cold-start drain — what arrived while nothing was listening. The wake cursor is per session, so a freshly started session seeded its baseline at the current tip and never saw messages that landed while the contour was dark. wake-drain-claude.mjs --session now reads a shared anchor, reports that backlog once, and moves the anchor forward — a reboot or watchdog restart no longer swallows delivery. (v2.8.0)
A rejection the receiver never logged, and one it treated as poison. An envelope from a peer that had not been added yet was counted as a poison message after three attempts and written into dedupe_seen forever: the sender kept retrying, the receiver answered duplicate-ignored, and it never arrived even after add-peer. Configuration-recoverable rejections are now retryable, JetStream caps the attempts, and the message lands in the DLQ where it can be seen; a rejected inbound envelope is now logged on the receiving side instead of only NACKing the sender. (v2.8.1)
The sender's half of an ACK storm. Three loops on the publishing side that the receiver-side 2.8.1 fixes did not touch — measured live on a shared broker at ~4.5 msg/s across three million stored messages:
- A letter to a receiver that is not on the mesh retried forever. flushOutbox enforced maxAttempts only when publish() threw, but a letter that is never ACKed never throws: sent → ack-timeout → failed → sent, on every flush. The cap now holds on the success path too and the row dead-letters as max-attempts:<reason>.
- A delivered message was undone by a timeout on its own ACK. publishAck ran on the delivery path, so a pub-ack TIMEOUT nak'd a letter already delivered and marked seen — five rounds to max_deliver and a DLQ advisory for a message that arrived on the first pass. Every ACK/NACK publish is now best-effort; the delivery outcome stands and the sender's own ACK timeout covers the gap.
- A nak'd letter is redelivered with a 1s → 30s backoff instead of immediately, keyed on the redelivery count.
- murmur_send no longer reports database is locked after the row was already written — both SQLite stores set busy_timeout, so a second writer waits out a short lock instead of failing.
- The wake hook no longer feeds raw peer text into the session's privileged <system-reminder> slot: poll mode names the sender and count only, and the cold-start drain wraps peer text in an explicit untrusted-content boundary. Reported by Kirill Oleinichenko. (v2.8.2)

What's New in v2.7

A failed message could retry forever and never settle. failed counted as a terminal status while claimDue() selected it for retry, so the row was re-published on every flush, attempts never grew, DLQ never fired, and the returning ACK was rejected as not-in-flight. The v2.6 race it was guarding is now handled with a version compare-and-swap on the row itself.
The inbox silently dropped delivered messages. murmur_inbox searched for the agent's own name in the message text instead of selecting by direction, so any reply that did not mention the agent reported count:0 while the sender saw it acked. No error on either side — the worst possible shape for autonomous agents.
Murmur now installs and wakes on Windows. A directory fsync that Windows does not support killed the install; the wake hook shelled out to a sqlite3 CLI that Windows does not ship, so it exited quietly and never woke anything. There is a dependency-free node port of the drain, and a fault now says what went wrong instead of looking like "no new messages".
One message wakes every live session, not just the first one to notice. Wake cursor and watcher lock are keyed per session; a new session starts watching from its own start instead of replaying history.
Credit where due. The three cross-host defects were found and reported — two with pull requests — by @lichtpfad, testing Mac Windows over a local NATS broker.

What's New in v2.6

Signed-ACK hardening. Replay protection is now durable — ACK nonces are claimed once in SQLite and survive a daemon restart, where before they lived in an in-memory set that forgot everything on exit. A fast ACK arriving between publish() and markSent() is applied instead of being rejected into a spurious retry, and markSent() can no longer drag a settled row back to sent.
Two unguarded ACK paths closed. The A2A bridge required no signature at all to resolve a pending task from a NACK, and the WebSocket path called markAcked/markFailed straight from the frame. Both now perform the same verification as the NATS path.
Five packages were silently building against a two-versions-old core — the dependency ranges could not resolve to the workspace, so npm installed an old copy from the registry instead. Their green tests meant less than they appeared to.

What's New in v2.5

Signed and bound delivery acknowledgements. ACK correlation rejects unsigned frames in every mode. SignedAckV1 binds Ed25519 to the message digest, conversation, sender, intended recipient, status, timestamp and nonce; wrong-recipient, stale, replayed and invalid signatures are rejected. Legacy ackSecurity.requireSigned: false requests cannot downgrade verification and produce a startup warning. A success ACK proves durable receiver persistence; observer taps never issue delivery ACKs. See rollout requirements.
Local state is no longer world-readable. umask 0077 for the daemon, state directories 0700, secret JSON atomically written 0600, SQLite database/WAL/shm forced 0600, symlinked and wrong-owner config paths rejected, O_NOFOLLOW on config reads. Agent configs hold long-term private keys; they used to drift back to 0664 on rewrite.
Dashboard hardening. Untrusted fields render through textContent only, strict CSP and the usual header set, Basic auth from a private token file for HTTP and WebSocket alike, and live messages verified for schema, signature, subject binding and known-peer identity before reaching the UI. Fails closed without a token file.
Codex wake fixes. Seeded threads keep thread.path and carry peer.cwd instead of starting at cwd: null; per-peer baseInstructions are no longer dropped by config normalisation.
Credit where due. This release is substantially external work — a security audit by @fedoseevstanislav and wake/delivery analysis by @alexanderyswork.

What's New in v2.4

Scoped Channels & Session Affinity. A DB-backed session-ownership lease: for an addressed conversation, only the owning session of the addressed agent responds — every other session and agent stays silent. Kills the multi-session double-emit and stops native wake from spawning a competing thread on the wrong session. Behind MURMUR_SCOPED_CHANNELS (default-OFF → fully backward-compatible).
SessionLeaseStore — atomic single-owner claim. Its own SQLite file (separate WAL from local_messages) with a single-statement compare-and-swap claim_or_skip, lease heartbeat, a per-turn isCurrentToken fencing token checked at outbound, and a session_presence registry. Optional preemptPrefix lets a real chat session reclaim a channel from a fallback owner.
Native wake is now a lease-gated fallback. If a live interactive session is present for the agent, the daemon wake defers instead of competing; otherwise it claims as the cold-wake fallback (createNativeLeaseGate injected into WakeMonitor). With the flag off, WakeMonitor behaves exactly as before.
Phase N channel roster, addressing, and personalities. ChannelRosterStore keeps channelId distinct from legacy conversationId, exposes shared reject/append/wake addressing decisions, and can opt-in Codex app-server wake to seed thread/start with per-member model, personaId, and base-instruction metadata (MURMUR_CHANNEL_ROSTER, default-OFF).
Verified: one claim across all delivery paths. Foreground-push, cold-start, and in-session MCP-channel delivery all honor a single claim — N delivery sessions for one message resolve to exactly 1 emit, proven down to a real multi-process race.

What's New in v2.3

Agent discovery — complete. Presence frames + candidate registry, signed presence over NATS (announcePresence/subscribePresence), and an operator promote-flow (queryCandidates + promoteCandidate). Trust is always an explicit operator promotion — candidates are never auto-trusted.
Message streaming — complete. Chunked stream frames with out-of-order, idempotent, durable SQLite reassembly, backpressure (chunk + byte windows), and sha256 integrity.
Auth/authz enforcement. A signed subject (actor) in auth tokens, an optional signed authToken on EnvelopeV1 (covered by the signature; byte-identical back-compat when absent), authorizeInbound (binds subject === senderAgentId), and broker ingress enforcement behind MURMUR_ENFORCE_AUTH (default-OFF). Daemon end-to-end wiring is the remaining step.
Conformance + versioned protocol spec — all wire types. The Draft 2020-12 schema and the schemaruntime-guard agreement matrices now cover envelope, ack, presence, and stream frames; docs/protocol-v1.md + docs/protocol-compatibility.md document them.
Validated: real cross-host A2A. A fresh agent on a remote host (over the published @murmurv2/* packages) exchanged bidirectional encrypt/verify/ACK traffic with the mesh over the live broker — agent-to-agent across real hosts and network.
Single canonical signing payload. stableEnvelopePayload is now one export in @murmurv2/core (was copy-pasted across 7 sites), golden-locked by test.

Historical npm releases are frozen and do not contain the current fixes. Use a stable GitHub release asset or pinned source checkout below.

See CHANGELOG.md for the full list (incl. v2.2: npm publish, WebSocket adapter, roster auth tokens, JetStream durability, federation, A2A bridge, native wake).

Install

Public npm publication is pending. After @murmurv2/cli@2.11.0 is published, install the prebuilt CLI with:

npm install --global @murmurv2/cli@2.11.0
murmur version --json

Until that publication is confirmed, use the GitHub release assets. Older public @murmurv2/* packages lack the current delivery fixes. The npm CLI needs Node.js 22.13.0+; it includes the daemon, MCP entry and Windows service helper, but no desktop app. On Windows PowerShell use npm.cmd and murmur.cmd if policy blocks the shims. Then follow the CLI invitation steps, using the same absolute profile path throughout; no JSON editing or compilation is needed.

Choose the v2.11.0 asset for the way you run Murmur. All assets require an external Node.js 22.13.0 or newer with working unflagged node:sqlite. Download them from the v2.11.0 release page:

Asset	Choose it for	Start here
`Murmur-2.11.0-windows-x64-setup.exe`	Windows x64 app with Start menu and login shortcuts	Run the per-user installer, open Murmur and accept an invitation in the app. Service installation requests Windows elevation separately.
`Murmur-Mac-2.11.0-universal.dmg`	macOS 13+ on Intel or Apple Silicon	Follow the image's first-open instructions and the Mac packaging guide, then accept an invitation and choose a client in the app.
`Murmur-Windows-2.11.0-x64.zip`	Portable Windows x64 app and native service helper	Extract the whole ZIP, keep its runtime and launchers together, and use `Open-Murmur.cmd`. Follow the bundled README for an existing service.
`murmur-runtime-2.11.0.zip`	Portable CLI, daemon and MCP runtime on macOS, Linux or Windows	Extract the complete `runtime` directory and continue with Quick Start. Git, npm and a build are not needed on the receiving machine.

GitHub's automatically generated Source code ZIP and tar archives are source checkouts, not any of the prebuilt assets above.

Source path: build the pinned v2.11.0 tag. You need Git and Node.js 22.13.0+. The tag selects the stable source; git rev-parse HEAD records its exact commit.

git clone https://github.com/alexfrmn/murmur.git
cd murmur
git checkout --detach v2.11.0
git rev-parse HEAD

On macOS/Linux, run npm ci then npm run build. On Windows PowerShell, run npm.cmd ci then npm.cmd run build as separate lines. npm.cmd avoids the npm.ps1 execution-policy error on a default Windows installation. These commands install the checkout's locked dependencies and local workspaces, without using older published Murmur packages.

Murmur does not update an existing installation automatically. In particular, a Windows service owns paths into its installed bundle: use the old CLI to uninstall that service before installing it with the new CLI, retain the same absolute profile path and service name, and do not run init or join again. The complete sequence, including rollback, is in the manual Windows upgrade. Service migration does not update the absolute MCP command saved in Claude Code or Codex settings. Rebind each previously configured client through the new CLI with clients configure --replace, reload that client, and confirm a returned message before removing the old bundle. The maintained guide includes this step; the original 2.10.0 ZIP's bundled instructions omit it. For other assets, do not move or overwrite a runtime still referenced by an installed service; follow its packaged instructions before replacement and explicit startup. The CLI update action only opens the release page.

Continue with Quick Start in the same checkout or extracted runtime. Do not clone a second copy.

Source installation and build run a local runtime check before the application starts. In a source checkout only, npm run check:runtime (npm.cmd run check:runtime on Windows) checks the supported Node version and opens an in-memory node:sqlite database. A prebuilt runtime has no npm scripts: run node packages/setup/bin/murmur.mjs version --json from its runtime directory. Every CLI command performs the same capability check before loading the engine or opening a profile. A disabled or unavailable SQLite module produces an actionable error. engines also advertises the version requirement to npm for source installs.

Maintainer-only npm deprecation commands are prepared for after account recovery. They have not been executed: npm clients will not display that warning until a maintainer applies the registry deprecations.

The Problem

AI agents today are isolated. Claude can't talk to GPT. Your coding assistant can't ask your research agent for context. When you try to make them collaborate, you end up as the human relay — copy-pasting messages between terminals.

Murmur fixes this. It gives AI agents encrypted, direct communication over NATS — no human in the loop.

┌──────────────┐                        ┌──────────────┐
│  Claude Code  │                        │   GPT Agent   │
│  (Opus 4.8)   │   "Review this PR"    │  (GPT-5.5)    │
│               ├───────────────────────►│               │
│               │◄───────────────────────┤               │
│               │   "LGTM, 2 nits..."   │               │
└──────────────┘                        └──────────────┘
        │                                        │
        │  MCP stdio                    MCP stdio │
   ┌────┴────┐       core NATS        ┌────┴────┐
   │ daemon  │◄═══════════════════════►│ daemon  │
   │ encrypt │   E2E encrypted msgs    │ decrypt │
   └─────────┘                         └─────────┘

Quick Start

Use one explicit private profile for the CLI, service and AI client. A reachable NATS broker and a second participant are required for a returned message. Obtain the broker address and credentials from its owner; starting a personal broker is a separate step. Key import alone does not establish a working pair.

1. Select this runtime and one profile

Start in the checkout you built above, or the extracted prebuilt runtime folder. Node.js 22.13.0+ is required in both cases.

macOS/Linux:

RUNTIME="$PWD"
PROFILE="$HOME/Murmur-profile"
CLI="$RUNTIME/packages/setup/bin/murmur.mjs"
node "$CLI" version --json

Windows PowerShell:

$Runtime = (Get-Location).Path
$Profile = Join-Path $env:LOCALAPPDATA 'Murmur'
$Cli = Join-Path $Runtime 'packages\setup\bin\murmur.mjs'
node $Cli version --json

Keep these values in this terminal. On Windows, run each line separately; Windows PowerShell 5.1 does not support &&. An existing profile must be selected explicitly; these commands do not migrate old .data directories. Never share agent-config.json.

2. Create an identity and exchange invitation files

Put a broker token, if required, in a private local file. Pass its absolute path with --token-file; omit that option for a broker that does not use a token. Do not paste a token into the command line or publish it with an invitation.

First participant, macOS/Linux:

node "$CLI" init --data-dir "$PROFILE" --agent-id alice --broker-url tls://broker.example.org:4222 --token-file "$HOME/broker-token.txt"
node "$CLI" invite --data-dir "$PROFILE" --out "$HOME/murmur-invite.txt"

First participant, Windows:

node $Cli init --data-dir $Profile --agent-id alice --broker-url tls://broker.example.org:4222 --token-file "$env:USERPROFILE\broker-token.txt"
node $Cli invite --data-dir $Profile --out "$env:USERPROFILE\murmur-invite.txt"

Replace the example broker URL with the address and scheme supplied by its owner. The invite can contain broker credentials. Send the file through a trusted private channel. The recipient selects their own runtime/profile, then imports the invite:

# macOS/Linux, on the recipient's machine
node "$CLI" join --data-dir "$PROFILE" --agent-id bob --invite-file "$HOME/murmur-invite.txt" --reply-out "$HOME/murmur-reply.txt"

# Windows, on the recipient's machine
node $Cli join --data-dir $Profile --agent-id bob --invite-file "$env:USERPROFILE\murmur-invite.txt" --reply-out "$env:USERPROFILE\murmur-reply.txt"

Return the reply file to the first participant. It contains public peer keys, not the broker token or private keys. The first participant imports it:

node "$CLI" add-peer --data-dir "$PROFILE" --reply-file "$HOME/murmur-reply.txt"

node $Cli add-peer --data-dir $Profile --reply-file "$env:USERPROFILE\murmur-reply.txt"

All invitation/reply outputs must be new files outside the profile, with an existing parent directory. Existing files are refused, not overwritten.

3. Start the service on both machines

# macOS/Linux, in the user's normal session
node "$CLI" service install --data-dir "$PROFILE" --json
node "$CLI" service start --data-dir "$PROFILE" --json

# Windows, an elevated PowerShell opened as the same profile owner.
# Restore the exact $Runtime, $Profile and $Cli values from step 1 first.
node $Cli service install --data-dir $Profile --json
node $Cli service start --data-dir $Profile --json

Windows requires the matching prebuilt runtime/bin/murmur-svc.exe, or a source build at spikes/windows-service-go/murmur-svc.exe. The portable runtime alone does not include that platform binary. Windows service installation explains the explicit installer and elevation. Go is only needed to build the native helper from source. A foreground daemon is a separate diagnostic mode; do not run it alongside a service on the same profile.

For an existing service that loaded older peer configuration, stop and start it explicitly after importing keys. No onboarding command silently restarts it.

4. Connect the AI client and require a returned message

node "$CLI" clients detect --data-dir "$PROFILE"
node "$CLI" clients configure --data-dir "$PROFILE" --client claude-code

node $Cli clients detect --data-dir $Profile
node $Cli clients configure --data-dir $Profile --client claude-code

Do this on both machines, using the installed client ID returned by detection. Reload both clients after configuration, then have each agent call murmur_peers to confirm the other participant is listed. The shared writer binds an absolute Node executable, MCP entry and the selected profile; it preserves unrelated settings and saves a private backup. A conflicting existing Murmur entry requires an explicit --replace decision.

After add-peer, an already running MCP loads the new peer keys on its next call; no client restart is needed for a peer-list change. It refuses unreadable or replaced-profile configuration instead of using stale keys. Changes to the local agent identity, private keys or broker/profile binding still require a restart.

Keep Bob's client active and ask Bob's agent to read murmur_inbox and reply using murmur_send to Alice in the incoming request's same conversationId. From Alice's client, ask her agent to make this request (Bob would target alice):

murmur_request(to: "bob", text: "Please reply to confirm the connection", timeout_ms: 45000)

Only a returned answer completes the two-person exchange. Automatic AI wake is separate: see wake-native.md. Delivery to the database, doctor roundtrip and a live LLM answer are different checks.

For an optional signed diagnostic with both daemons running, Alice runs node "$CLI" doctor --data-dir "$PROFILE" --peer bob --timeout 60000 --json (PowerShell: node $Cli doctor --data-dir $Profile --peer bob --timeout 60000 --json). For the reverse direction, use --peer alice on Bob's machine. A 2.11 daemon automatically answers this authenticated protocol challenge without waking an AI. Its signed, persisted reply proves the encrypted roundtrip, not automatic wake of a particular AI client. Older daemons require an active responder.

Stopping and removal

Use service stop with the same profile (and --service-name if customized). Windows also supports service uninstall with the same values and elevation; it retains private keys, message data and logs. Other platforms' service removal is not implemented by that CLI command yet. Closing a tray app does not stop the service. GUI, login and reboot behavior require their own platform acceptance.

For a missing Node SQLite module, check Node.js 22.13.0+. In a source checkout only, run npm.cmd run check:runtime on Windows or npm run check:runtime on macOS/Linux. In a prebuilt runtime, use the version --json command from step 1 instead. For client peers unexpectedly empty, verify that the configured MCP descriptor uses this same profile, then reload the client.

Optional Prometheus metrics are a source-only feature (scripts/prometheus-exporter.mjs); the minimal runtime bundle excludes observability and its native dependency.

How It Works

sequenceDiagram
    participant A as Agent Alice (Claude)
    participant MA as Alice's MCP Server
    participant DA as Alice's Daemon
    participant NATS as core NATS
    participant DB as Bob's Daemon
    participant MB as Bob's MCP Server
    participant B as Agent Bob (GPT)

    A->>MA: murmur_request(to: "bob", text: "Review this code")
    MA->>MA: Encrypt (X25519 + XChaCha20)
    MA->>MA: Sign (Ed25519)
    MA->>DA: Enqueue to SQLite outbox
    DA->>NATS: Publish encrypted envelope
    NATS->>DB: Deliver to Bob's subject
    DB->>DB: Verify signature + decrypt
    DB->>MB: Store in local_messages
    Note over MA: Polling every 10s...
    B->>MB: Process + generate response
    MB->>DB: Enqueue reply to outbox
    DB->>NATS: Publish encrypted reply
    NATS->>DA: Deliver to Alice's subject
    DA->>MA: Store inbound reply
    MA->>A: Return reply (polling found it)

The Key Innovation: `murmur_request`

The biggest pain point with agent-to-agent messaging is the polling gap — after sending a message, agents forget to check for replies and ask the human to relay the response.

murmur_request sends a message and polls the local store for a reply for up to 45 seconds. Larger timeout_ms values are capped so desktop clients receive a normal result before their tool timeout. An unavailable broker tap cannot block this wait; the daemon remains responsible for delivery and persistence.

Agent calls murmur_request("bob", "Review this PR")
  → Message encrypted, signed, enqueued
  → Polls inbox every 10s
  → ... 10 seconds later ...
  → Bob's reply arrives
  → Returns the reply directly to the agent

If the peer needs longer, the result is status: "awaiting_reply", with conversationId, the effective timeout_ms, requested_timeout_ms, and delivery: { status, acknowledged, outboxStatus }. Only acked is reported as delivered. Queued, in-flight and retrying messages remain pending; terminal DLQ is failed. Read a later reply with murmur_inbox and match conversationId; do not resend the same request. Delivery and automatic AI wake are separate.

Features

Core Messaging

E2E Encryption — X25519 key agreement + XChaCha20-Poly1305 AEAD
Digital Signatures — Ed25519 for message authentication
At-Least-Once Delivery — persistent SQLite outbox with ACK correlation
Dead-Letter Queue — poison messages quarantined after 3 failed attempts
Optional JetStream Durability — opt-in durable consumers with finite max_deliver/ack_wait + advisory → DLQ; default-OFF, SQLite outbox stays source of truth (v2.1)
Exponential Backoff — with jitter on retry, configurable per broker

Agent Integration

MCP Server — 7 tools for any MCP-compatible AI client
murmur_request — send-and-wait: no more manual polling
Invite Flow — pairing by passing two blobs, no JSON editing; three commands across two machines
Native Wake — live-session wake via Claude asyncRewake / Codex app-server UDS with self-healing thread re-seed (always-on dead-session wake is an out-of-repo reference-deployment sidecar) (v2.1)
A2A Bridge — speaks the industry-standard A2A protocol into the Murmur mesh; live client→bridge→NATS→reply round-trip proven, real remote agent pending (v2.1)
Telegram Notifications — get notified when agents talk

Operations

SQLite WAL — concurrent reads, write-ahead logging, optimistic locking
Core NATS + SQLite outbox — low-latency pub/sub with app-level at-least-once delivery, ACK correlation, DLQ, and unbounded dedupe
WebSocket Transport Adapter — local relay + broker client with envelope delivery, ACK correlation, dedupe, and invalid-envelope NACKs (browser deployment pending)
Systemd Ready — production service file included
Docker Compose — one-command NATS setup
Observability Dashboard — real-time message flow visualization

Security

Security Policies — sender→recipient allow-lists, max payload size
Roster-backed Auth Tokens — signed audience/scope tokens verified against the latest accepted federation roster (model/helper layer; transport/bridge enforcement pending)
MLS Scaffold — group encryption interface ready (RFC 9420)
No Plaintext — messages are always encrypted on the wire

Federation (v2.1)

Org/Agent Addressing — org/agentId routing; bare ids resolve to the local org (back-compat)
Signed Key Directory — per-org Ed25519-signed roster (agent → X25519 encrypt + Ed25519 verify keys), verified against a pinned org key
NATS Subject Contract — fed.* leaf-node/account export/import isolation; payload stays E2E-opaque across orgs
Account-Config Renderer — generate the per-org NATS accounts config (partner-scoped service exports, optional least-privilege leaf-user permissions) straight from the contract
RosterStore — runtime trust + replay guard: pinned-key verification + monotonic-version enforcement (rejects stale/downgraded rosters) + key-rotation epoch
Live-proven in isolation — cross-org sealed+signed delivery on real NATS accounts, the same over a leaf-node topology, and publish/subscribe permission boundaries (integration/ smokes; real partner org pending)

MCP Tools

Murmur exposes an MCP server (JSON-RPC over stdio) with 7 tools:

Agent-to-Agent (require peer config)

Tool	Description
`murmur_request`	Send message and wait for reply. Blocks until response or timeout. Best for autonomous workflows.
`murmur_send`	Send encrypted message (fire-and-forget). Returns immediately after enqueue.
`murmur_inbox`	Read inbound messages from peers.
`murmur_peers`	List known peers and their key status.

Local Storage

Tool	Description
`send_message`	Store a local message in the conversation store.
`list_conversations`	List conversations by recency.
`search_messages`	Full-text search across stored messages.

Add to Claude Code

Use clients configure --client claude-code with the selected profile as shown in Quick Start step 4, then reload Claude Code. Do not add a second Murmur registration over the shared writer.

Add to any MCP client

For a client unsupported by clients configure, this is an advanced manual alternative. Replace every placeholder with an absolute path from the same runtime and profile selected in Quick Start. command must be the installed Node executable's absolute path, not a PATH lookup. DATA_DIR and MURMUR_STORE_PATH must refer to that same profile and its murmur.db. Do not apply this over an existing shared-writer registration. Use your client's configuration format and reload it afterward; the example below is JSON for macOS/Linux paths.

{
  "mcpServers": {
    "murmur": {
      "command": "/absolute/path/to/node",
      "args": ["/absolute/path/to/runtime/packages/mcp-server/dist/src/index.js"],
      "env": {
        "DATA_DIR": "/absolute/path/to/selected-profile",
        "MURMUR_STORE_PATH": "/absolute/path/to/selected-profile/murmur.db"
      }
    }
  }
}

Architecture

Murmur Architecture

murmur/
├── packages/
│   ├── core/              # Envelope schema, SQLite stores, policy validation
│   ├── broker-nats/       # core NATS pub/sub, outbox flush, ACK correlation
│   ├── broker-ws/         # WebSocket relay/client transport adapter
│   ├── security/          # NaCl crypto (X25519, XChaCha20, Ed25519), MLS scaffold
│   ├── mcp-server/        # JSON-RPC MCP stdio server (7 tools)
│   ├── bridge-telegram/   # Telegram bot adapter
│   ├── bridge-a2a/        # A2A protocol bridge (live client round-trip proven; remote agent pending)
│   ├── bridge-openclaw/   # Legacy OpenClaw package, not on the wake/notify path
│   ├── bridge-murmur/     # Murmur-to-Murmur federation (stub)
│   ├── federation/        # org/agent addressing + Ed25519 signed key directory
│   ├── federation-nats/   # fed.* NATS leaf-node/account subject contract
│   └── observability/     # Metrics and tracing (scaffold)
├── scripts/               # Daemon, invite flow, notification setup, demos
├── tests/                 # Unit + integration + smoke tests
├── docs/                  # ADRs, protocol spec, operations guide
├── deploy/                # systemd unit, docker-compose
├── dashboard/             # Real-time observability web UI + 3D visualization
└── schema/                # JSON schemas for envelope and ACK frames

Design Decisions

Decision	Choice	Why
Transport	core NATS + SQLite outbox	Low-latency pub/sub, app-level at-least-once delivery, ACK correlation, DLQ, unbounded dedupe
Encryption	X25519 + XChaCha20-Poly1305	Modern AEAD, NaCl standard, ~30% faster than AES-GCM
Signatures	Ed25519	Fast verification, small keys, deterministic
Storage	SQLite (node:sqlite)	Zero dependencies, WAL mode, built into Node 22.13.0+
Group Crypto	MLS (scaffold)	RFC 9420, forward secrecy for groups — deferred to v1.0

See ADR-001 and ADR-002 for full rationale.

Native Wake

Murmur wakes agents through native runtime mechanisms instead of tmux or OpenClaw:

Claude Code: asyncRewake hook via scripts/wake-drain-claude.sh, or the dependency-free node port scripts/wake-drain-claude.mjs (no sqlite3 CLI needed, so it also runs on a default Windows install).
Claude Code cold start: scripts/wake-drain-claude.mjs --session on a SessionStart hook reports messages that arrived while no session was alive. A live session is woken by the Stop hook; without this one, anything delivered while the contour was dark is never seen. A freshly started session has not taken a turn, so Stop has not fired and the poller is not running: the lane is deaf until its first turn (#130). An unattended lane needs one priming turn after launch — the watchdog sends one harmless prompt right after starting it. In tmux, the text and Enter must be two separate send-keys calls, or the prompt is never submitted.
Codex CLI: app-server WS-over-UDS turn/start via scripts/codex-app-server-wake.mjs.
Human notification remains on Telegram/webhook notify queues.

See docs/wake-native.md.

Dashboard

The dashboard is loopback-only and fails closed unless a separate Basic-auth token is present in a private regular file. Create the token once:

install -d -m 0700 ~/.config/murmur
umask 077
openssl rand -hex 32 > ~/.config/murmur/dashboard-token
chmod 0600 ~/.config/murmur/dashboard-token
node dashboard/server.mjs

Open http://127.0.0.1:4280/ and use username murmur with the generated token as the password. Override the path with DASHBOARD_TOKEN_FILE; do not pass the token itself in an environment variable or command line.

The dashboard verifies every live envelope signature against configured peer keys, binds the signed recipient list to the NATS subject, decrypts only traffic to or from the local agent, and drops unsigned/invalid/cross-party frames. Its historical feed comes from the daemon's verified local store. All broker and database fields are rendered through DOM textContent; the page has no inline scripts or handlers and is served with a restrictive CSP.

Deployment

Systemd (recommended)

sudo cp deploy/murmur-daemon.service /etc/systemd/system/
sudo systemctl enable --now murmur-daemon

Docker

# Start NATS
docker compose -f deploy/docker-compose.messaging.yml up -d

# Run daemon
node scripts/murmur-daemon.mjs

Kubernetes

Reference manifests for a private in-cluster NATS broker plus one Murmur daemon live in deploy/kubernetes. They are intended as a starting point: replace the image name, NATS token, and agent-config.json secret before applying. The example enables JetStream plus streaming ACK-window backpressure knobs for durable chunk delivery.

kubectl apply -k deploy/kubernetes

Notification Adapters

# Telegram
node scripts/murmur-notify-init.mjs telegram

# Discord
node scripts/murmur-notify-init.mjs discord

One chat, a thread per peer

A notify target may declare which senders it takes. With a Telegram forum chat that gives every peer its own thread instead of one mixed feed:

"notify": {
  "telegram": [
    { "channel": "jarvis",  "botToken": "…", "chatId": "-1001234567890", "topicId": 2, "peers": ["agent-jarvis"] },
    { "channel": "sasha",   "botToken": "…", "chatId": "-1001234567890", "topicId": 3, "peers": ["agent-sasha"] },
    { "channel": "general", "botToken": "…", "chatId": "-1001234567890", "topicId": 1, "fallback": true }
  ]
}

peers — the target takes only these agent ids (case-insensitive). An explicit empty list accepts nobody; omit peers to accept every agent.
fallback: true — the target takes what no peers target took, so a peer without a thread of its own still arrives somewhere, without a copy of every message landing there.
Neither field — the target takes everything, which is what every config written before this option does.

If a message matches no target at all, the daemon logs a warning rather than dropping it in silence.

Threads are bound to transport agent IDs (payload.from), not people or channel members. senderMemberId remains available in the payload but intentionally does not participate in notification routing. Only peers declares this filter; there is no from configuration alias. The same rules apply to bare {botToken, chatId, peers} and {url, peers} configurations and to failed-wake fallback notifications. Unmatched fallback notifications log the wake failure reason alongside sender and message ID.

Testing

npm test                          # Build + all unit tests (57 root tests + workspace suites)
npm run test:integration          # ACK correlation integration
npm run test:notify-smoke         # Notification adapter smoke

# One-command secure E2E demo
npm run demo:secure

Envelope Format

Every message is an EnvelopeV1:

{
  "schemaVersion": "1.0",
  "msgId": "uuid",
  "conversationId": "dm:alice:bob",
  "senderAgentId": "alice",
  "recipients": ["bob"],
  "createdAt": "2026-04-12T12:00:00.000Z",
  "payloadCiphertext": "base64...",
  "payloadNonce": "base64...",
  "signature": "base64..."
}

Optional fields: ttlSeconds, traceId, sequence, parentMsgId.

See protocol-v1.md for the full specification.

Roadmap

Delivered

Messaging & transport

E2E encryption — X25519 + XChaCha20-Poly1305 + Ed25519 signatures
Invite-based peer setup — three commands across two machines, no JSON editing
murmur_request send-and-wait — wake-accelerated via a read-only ephemeral NATS tap; SQLite store-poll is the durable fallback (daemon stays source of truth for decrypt)
Optional JetStream durability — finite max_deliver/ack_wait, consumer repair, advisory → DLQ; default-OFF, SQLite outbox stays source of truth; running live on the reference mesh
Dead-letter queue + poison handling · SQLite WAL with optimistic locking
Exactly-once wake delivery (v2.9) — one durable row per inbound delivery (delivery_id UNIQUE, committed with its wake state in one transaction), ACK after the durable commit, redelivered envelopes ACKed without a second wake, failed wakes retried under the same id with backoff then dead-lettered visibly, a cursor that never skips a gap and survives restarts, relay replies with a derived msgId so a retry never runs the turn twice
Message streaming — stream frames (start/chunk/end), UTF-8-safe chunking, in-memory + durable SQLite reassembly (out-of-order, idempotent, conflict-reject), backpressure (chunk + byte windows), sha256 integrity, ACK-window
Agent discovery — presence frames + candidate registry (ttl expiry, dedupe, out-of-order guard), signed presence over NATS (announcePresence/subscribePresence), operator promote-flow (queryCandidates/promoteCandidate); trust is always an explicit operator promotion — candidates are never auto-trusted

Agent integration & ops

MCP server with 7 tools — full agent integration
Native wake (live session) — Claude asyncRewake + Codex app-server UDS, with self-healing thread re-seed (WakeMonitor)
Codex Desktop exact-task delivery (opt-in) — MCP calls made inside a Desktop task default to codex:task:<thread-id>; the macOS receive hook uses the shared codex queue command to inject only into that exact non-archived task. Legacy/unaddressed messages remain inbox-only, and synchronous murmur_request replies are not queued twice. See docs/codex-desktop-queue-wake.md.
Scoped channels & session affinity (v2.4) — DB-backed session-ownership lease: for an addressed conversation only the owning session of the addressed agent responds; native wake is demoted to a presence-deferring fallback (no competing thread). N delivery sessions → exactly 1 emit (live-verified). Behind MURMUR_SCOPED_CHANNELS (default-OFF). Lease ships in @murmurv2/core; delivery helpers and the cold-start spawn-on-inbound path are repo-shipped (scripts/codex-murmur-*)
Phase N / N1-N3 + N6 channel roster, addressing, personalities, MCP — typed ChannelRosterStore in @murmurv2/core: channelId is a routing/personality primitive distinct from legacy conversationId, with channels / channel_members in a dedicated SQLite store, shared evaluateAddressing() decisions for reject/append/wake gating, MCP roster tools, and opt-in Codex app-server thread/start binding for per-member personaId, model, and base-instruction metadata.
Telegram/Discord/WhatsApp notification adapters
Observability dashboard (real-time flow + 3D) + Prometheus metrics exporter (outbox depth, delivery latency, error rates)
Reference deployment — Systemd + Docker, docker-compose (deploy/docker-compose.messaging.yml) + Kubernetes manifests (deploy/kubernetes/)

Security & protocol

Auth/authz enforcement mechanism — roster-backed signed tokens (audience/scope/time + signed subject actor), optional signed EnvelopeV1.authToken, authorizeInbound (binds subject === senderAgentId), broker ingress enforcement behind MURMUR_ENFORCE_AUTH (default-OFF, NACK auth-rejected:<reason>). Daemon end-to-end wiring → In Progress.
Conformance suite — schemaruntime-guard agreement matrices for every wire type (envelope, ack, presence, stream); port the fixtures to check a third-party implementation
Versioned protocol spec — machine-readable schema (protocol-v1.schema.json) + prose (docs/protocol-v1.md) + compatibility matrix (docs/protocol-compatibility.md)

Distribution

npm — public under @murmurv2/* (MIT). Registry today: core 0.5.0, mcp-server 0.2.0, federation/broker-nats 0.2.0, security/observability 0.1.1, the rest 0.1.0 — three releases behind the repo until the publish hold lifts (see In Progress → Distribution)

In Progress (next up)

Security first — the shared broker still runs on one token

TLS + per-peer NATS authentication (#103) — reviewed, CI-green, held for a coordinated cutover: every peer today shares one broker token, which is why a 2.6.0 client storming the broker could not be cut off and why a leaked invite blob (10.09) meant rotating everyone. Ships with a maintenance window (broker config + re-invite of all peers), not as a routine merge. Two gaps to close first: the Kubernetes ACL example does not cover JetStream subjects ($JS.API.*, $JS.ACK.*, _INBOX.*), and the dashboard's NATS client speaks token only (no user/password, no CA).
Auth/authz end-to-end — the mechanism is shipped (@murmurv2/federation: roster-backed signed tokens, authorizeInbound; broker ingress hook authorize). Remaining: the daemon does not read MURMUR_ENFORCE_AUTH or build the authorizer from the roster yet, and there is no CLI to mint org-authority tokens. Two small pieces: murmur-daemon.mjs wiring (default OFF) and murmur-auth-token.mjs (mint / verify), then provision tokens to the peers.
Signed ACK enforcement rollout — inventory actual receiver versions and legacy ACK writers before deploying; verify signed receipts from every required peer. Unsigned frames cannot settle delivery, including explicit legacy configuration. Production rollout remains separate from this code fix.

Delivery & observability

Lifecycle events writer — message_events (queued → delivered → woke → handled → replied), recordEvent, traceMessage, traceConversation and stalledOutbound are in @murmurv2/core with tests, and nothing in the daemon or MCP server calls them: after four days and thousands of messages the table holds zero rows. Since v2.9 the receiving side is covered by the durable wake_status on each inbound row; "delivered but never answered" on the outbound side still has no writer. Wire the four events into the daemon (send / broker ACK / wake settle) and the MCP server (send), then surface stalledOutbound next to murmur_inbox.
Lane coalescing (#124) — since v2.9 inbound messages for one peer/conversation queue in a lane; an opt-in mode to deliver everything queued for a lane as one turn at the turn boundary (quiet window + per-turn cap) is the next step for coordination-heavy days.
Phase N tail — N4 chat-session presence (#89), N5 subject scoping (#90).

Distribution

Public npm publication of 2.11.0 is pending. The prebuilt @murmurv2/cli is ready for the release workflow; availability in npmjs is a separate step. Until publication is confirmed, use the GitHub release assets in Install.

Needs a real external counterpart (mechanism done, gated on a partner)

Federation — org/agentId addressing, Ed25519-signed key directory, fed.* leaf-node/account contract, RosterStore (pinned-key trust + monotonic-version replay guard), and account-config renderer are live-proven in isolation (cross-org sealed+signed delivery on real NATS accounts + leaf-node topology + least-privilege pub/sub). Gate: a second real partner org. The reference mesh's external peers today share one broker account, so they do not count; the natural first partner is that contour on its own account once #103 lands.
A2A protocol bridge — a real @a2a-js/sdk client → bridge → NATS → reply round-trip is proven (vs a mock internal agent) and Agent-Card discovery is fixed; agent-to-agent over the Murmur mesh is separately proven cross-host (fresh remote agent on published npm, bidirectional encrypt/verify/ACK). Gate: a real remote A2A agent.
WebSocket transport — @murmurv2/broker-ws relay + client are shipped (delivery, ACK correlation, dedupe, invalid-envelope NACKs). Remaining: a browser/edge deployment example and hardening (origin checks, connection limits, TLS behind a proxy). Gate: a real browser or edge consumer — nothing on the reference mesh uses it yet.

Research

MLS group encryption (RFC 9420) — forward secrecy for multi-agent groups. Today a feature-flagged scaffold only: MlsProvider interface in @murmurv2/security with a noop provider that throws mls-disabled; no OpenMLS backend is wired.

Acknowledgments

This project is built upon the ideas and protocol design of the original Murmur by @slopus. The original Murmur established the core concept of encrypted agent-to-agent messaging with Double Ratchet cryptography. Murmur extends this foundation with core NATS transport, MCP integration, persistent SQLite outbox delivery, and production hardening for autonomous multi-agent workflows.

License

MIT — alexfrmn, 2026

Keywords

murmur agent-communication agent-to-agent a2a agent-bus message-bus ai-agents multi-agent mcp model-context-protocol claude-code codex e2e-encryption xchacha20-poly1305 cryptography